The Problem

The elbow is a complex joint with its stability dependent on both its bony articulations and soft tissue restraints. The lateral collateral ligament (LCL) complex is the soft tissue component that confers stability to varus stress of the elbow joint. The supinator, common extensor origin, anconeus and brachialis provide additional dynamic muscular stabilization of the LCL complex. The LCL origin is from the lateral epicondyle of the distal humerus and consists of four major structures:

Lateral ulnar collateral ligament (LUCL)

Annular ligament

Lateral radial collateral ligament

Accessory lateral collateral ligament

LCL injury causes the proximal ulna and radius to rotate externally from the humerus with supination/varus stress.

Two main classifications of lateral ligament instability are used:

Posterolateral rotary instability (PLRI): due to insufficiency of the LUCL

The LCL complex typically avulses from its lateral epicondyle, along with laterally based capsule and extensor origin tissue.

Clinical Presentation

Lateral ligament injuries of the elbow typically occur due to a history of trauma in the setting of elbow dislocation. They can also be caused iatrogenically - with a common example being an LCL injury during surgical treatment of lateral epicondylitis. LCL injuries may also be seen following pediatric distal humerus fractures with residual varus malunion and gunstock deformity.

Patients complain of pain with clicking/snapping or locking of the elbow, but can have a painless full arc of motion. Symptoms occur with the forearm in a supinated position, with the elbow in a more extended position. Patients may report a history of recurrent elbow dislocations. Similar to posterior instability in the shoulder, the main complaint is pain rather than a complaint of instability.

Diagnostic Workup

The physical examination begins with inspection for signs of injury such as swelling, and palpation for tenderness. A careful neurological and vascular examination is performed. Elbow range of motion should be tested with care to check for mechanical blocks to motion and/or the presence of crepitus. Careful ligamentous exam is performed for lateral instability with comparisons made to the contralateral uninjured side.

Difficult to elicit in an awake patient. Most amenable for examination under anesthesia.

Patient supine with arm forward flexed overhead.

Hold forearm fully supinated with elbow in full extension.

Bring to flexion while applying valgus and supination stress with axial compression.

A positive test results in reduction of the radiocapitellar joint as the elbow is brought to flexion.

Full flexion will reduce proximal radius.

Apprehension with this maneuver can also be considered positive in the appropriate clinical setting since this exam is often difficult to perform while the patient is awake.

Ask patient to push up from chair - apprehension or feeling of instability is considered positive.

Ask patient to do push up on floor - apprehension when approaching full extension is considered positive.

Good quality radiographs are essential - always get a true lateral view. The images are assessed for joint congruency. Fluoroscopy can be useful for stress testing - can apply varus stress and look for joint space widening laterally. MRI is useful for evaluation of ligament ruptures and associated osteochondral injury. Ultrasound is cheaper than MRI, though operator and institution dependent.

Non–Operative Management

In the setting of traumatic/symptomatic lateral ligament injuries of the elbow, there is little role for non-operative management. Immobilization in a position of stability (based on range of motion exam and/or fluoroscopy may be attempted. This often results in elbow stiffness requiring later contracture release; but a stiff stable elbow is a fixable problem, while a chronically unstable elbow is more difficult to treat.

Indications for Surgery

Surgery is indicated for any patient with symptomatic lateral instability/PLRI

Surgical options include:

LCL repair - in the acute setting

LCL reconstruction - in more severe acute, or in chronic setting

Docking technique

Jobe technique

Interference screw technique

Surgical Technique

General Considerations

Supine position is used most often, but based on surgeon preference, a lateral decubitus position with elbow at 90 degrees over a bolster may also be used.

Pneumatic tourniquet.

Lateral incision as described by Kocher - interval between anconeus and extensor carpi ulnaris.

It is not uncommon to find a full avulsion of the LUCL and the common extensor tendon, with bare bone exposure of the lateral epicondyle.

Anatomically based on an isometric point - test with elbow range of motion.

Tensioning should be performed with the elbow at 60 degrees of flexion, and in forced pronation.

It has been recommended to place the humeral origin at the isometric point.

This can be identified by placing a K-wire at the proposed location, wrapping the suture from the lateral ligament complex around the wire multiple times, and ranging the elbow.

The correct isometric point will have consistent tension on the suture.

External fixation is rarely, if ever, necessary in pure laterally based ligamentous elbow injuries, but may play a role in the setting of more severe trauma such as elbow fracture-dislocations or global elbow instability.

Before final tensioning, the elbow should be ranged with tension on the graft to remove creep.

Acute/Repair

If tissue quality/quantity is adequate, repair can be performed.

Identify avulsed ligamentous structures.

May use a suture anchor at the proximal attachment site on the lateral epicondyle.

Place grasping suture (Krakow) within the LCL complex (#2 or #5 nonabsorbable suture).

Summary

Lateral elbow instability is a problem that often requires surgical management. It typically occurs in a traumatic setting. Many operative techniques exist as listed in this text, though a single technique has not been shown to be more effective in treatment. Careful history and physical examination is paramount in making the diagnosis. It is important to discuss the nature of the injury and the importance of rehabilitation in treating this difficult orthopaedic problem.

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